They’re going to have either Sally only run into Leatherface in the final climatic moment, or have some conveniences that she never gets a good shot at him.
Leatherface isn’t like Michael Myers where even a prepared Laurie could still potentially lose to him. He’s just a dude with no supernatural levels of durability and also lacks any skills in the stealth department usually once he gets mad. So it’s why it’s usually best to always have him terrorizing some unsuspecting and unarmed people because if guns start being aimed at him he‘d be fucked.
Also, dude has to be in his 70’s by now at least. Again, Michael has the supernatural angle to explain why’s he kicking ass even now in his 60’s (always hated that dumb cop in H20 who said Michael wasn’t a threat due to his age, how is someone in their 40’s not a threat?!) but Leatherface doesn’t. I mean, he must be never skipping leg day and also lifting some weights constantly to be able to still lift a guy in the air at his age.
I dunno, I feel the franchise works better to just stay set in the 70’s or 80’s if they want to keep making new ones. Even the 2003 remake was still set in the 70’s IIRC.
Granted, it has to be at least be better than the 2006 and 2013 films (and the 4th film in the 90’s, though that one is enjoyable on a batshit crazy level, especially with the random-as-hell Illuminati element. Yes, for those who never saw it, that legit happens). Never saw the 2017 prequel.